ITR: Efficient Self-Organizing Content Distribution Network for Scalable Video Streaming Services

作为IP组播的后继技术，应用层组播和覆盖网络已经成为当前Internet中的两个非常重要的技术，它们有望为大规模的Internet用户提供一个高度可扩展的并发信息传输平台。本计画以下一代覆盖网路为研究对象，探讨建立一个分散式、自组织式的即时视讯串流内容分发架构。与以前的方法不同，我们的工作不依赖于延迟作为距离的度量，而是利用现有互联网的拓扑和路由结构来计算距离和创建本地拓扑。使用拓扑感知发现的邻居的每个副本服务器，节点建立高效的网格复制的静态内容和构建自组织组播覆盖树的实时流媒体直播视频材料。特别注意确保整个架构具有高度可扩展性，适合在现有Internet上的实际使用。一旦安装，建议的内容分发网络（CDN）中的每个节点自动发现其在互联网中的位置，连接到CDN结构的控制树，并找到其邻域中的其他节点。控制树中的信息包含CDN网络的节点对互联网的所有独立发现的视图的可缩放聚合。使用此控制树，节点快速构建到达主数据服务器的相邻网格的重叠集合。到达的最终用户被有效地引导到最近的缓存基于他们在互联网和网络集群中的位置已经发现的各个缓存节点。为了避免数据包丢失，并控制流沿着的分支的组播树，我们调查新的拥塞控制方法，视频流，允许平滑播放，并保持稳定的延迟反馈下从网络。CDN已成为现有Web基础设施的重要组成部分，并已改善了许多Internet下载的响应时间和吞吐量。支持视频流的未来CDN将提供一个可扩展的平台，用于向最终用户分发实时和预录制的视频节目，并将大大提高社会传播信息的能力。拟议的研究活动将纳入网络课程。这将使学生能够深入了解与对等网络和内容分发网络相关的架构设计问题。

As successors of IP multicast, application-layer multicast and overlay networks have become two very important technologies in the current Internet that promise to provide a highly scalable platform for concurrent delivery of information to large groups of Internet users. This project focuses on next-generation overlay networks and studies the problem of building a distributed, self-organizing content distribution architecture for real-time video streaming services. Unlike previous approaches, our work does not rely on delay as the metric of distance, but rather utilizes the topological and routing structure of the existing Internet to compute distances and create local topologies. Using topologically aware discovery of the neighborhood of each replica server, nodes build efficient meshes for replication of static content and construct self-organizing multicast overlay trees for real-time streaming of live video material. A special attention is paid to making sure that the entire architecture is highly scalable and suitable for practical use over the existing Internet. Once installed, each node in the proposed content distribution network (CDN) automatically discovers its location in the Internet, attaches to the control tree of the CDN structure, and finds other nodes in its neighborhood. The information in the control tree contains a scalable aggregation of all independently discovered views of the Internet by the nodes of the CDN network. Using this control tree, the nodes quickly build an overlapping set of neighborhood meshes that reach the main data server. Arriving end-users are efficiently directed to the nearest cache based on their location in the Internet and network clusters already discovered by the individual cache nodes. To avoid packet loss and to control the flows along the branches of the multicast tree, we investigate new congestion control methods for video streaming that allow smooth playback and remain stable under delayed feedback from the network. CDNs emerged as a crucial part of the existing web infrastructure and already improve the response time, as well as the throughput, of many Internet downloads. Future CDNs that support video streaming will deliver a scalable platform for distributing live and pre-recorded video programs to end-users and will greatly improve the current ability of the society to disseminate information. The proposed research activities will be integrated in the network course curriculum. This will enable students to gain deep understanding of the architectural design issues related to peer-to-peer networking and content distribution networks.